Ribbed convolution muffler



FIG. 1 is a perspective view of a ribbed convolution muffler depicting a new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a bottom plan view thereof;

FIG. 4 is a front view thereof;

FIG. 5 is a rear view thereof;

FIG. 6 is a left side view thereof;

FIG. 7 is a right side view thereof;

FIG. 8 is cross-sectional view thereof taken along the line marked 8 in FIG. 2; and,

FIG. 9 is a cross-sectional view thereof taken along the line marked 9 in FIG. 2. 

CLAIM The ornamental design for a ribbed convolution muffler, as shown and described. 